Use NSTextStorageDelegate instead of method swizzling

[tomekzaw]

Details

Work in progress.

This PR is supposed to fix these issues:

• Spellcheck for previous words gets removed while typing on iOS #34
• Use ISA swizzling instead of method swizzling on iOS #102
• Migrate away from TextKit 1 to TextKit 2 #145
• Backticks are not removed when entering diacritics using option key commands on iOS #181
• Migrate from NSRange to UITextRange on iOS #191
• Cannot select single words on first attempt in text with headings or blockquotes on iOS #417
• Can't input some other language, such as Chinese #452
• Font size doesn't change immediately when updating styles on iOS #540

Related Issues

GH_LINK

Manual Tests

Linked PRs

[tomekzaw]

Regression: Cursor is shifted to the right when adding a newline after a blockquote

Screen.Recording.2024-10-17.at.11.38.34.mov

[tomekzaw]

Bug: spellcheck completely disappears when adding Markdown syntax

Screen.Recording.2024-10-21.at.20.50.18.mov

[tomekzaw]

Regression: Emojis are not visible

edit: [attributedString addAttributes:defaultTextAttributes range:fullRange]; breaks emoji font

edit2: fixed in 67968ec and explained better in 6e40703

[tomekzaw]

Regression: toggling text color doesn't work (it only works when you toggle markdownStyle first)

edit: it works if text doesn't contain any emojis

edit2: fixed in d377043 and explained better in 6e40703

[j-piasecki]

🪨

[j-piasecki]

🪨 🪨

[tomekzaw]

TODO: confirm that removing NSOriginalFont doesn't break anything (like copying text with emojis from MarkdownTextInput)

react-native-live-markdown/apple/RCTMarkdownUtils.mm

Lines 66 to 74 in 1fa1b54

	/*
	When updating MarkdownTextInput's `style` property without changing `markdownStyle`,
	React Native calls `[RCTTextInputComponentView _setAttributedString:]` which skips update if strings are equal.
	See https://github.com/facebook/react-native/blob/287e20033207df5e59d199a347b7ae2b4cd7a59e/packages/react-native/React/Fabric/Mounting/ComponentViews/TextInput/RCTTextInputComponentView.mm#L680-L684
	The attributed strings are compared using `[RCTTextInputComponentView _textOf:equals:]` which compares only raw strings
	if NSOriginalFont attribute is present. So we purposefully remove this attribute to force update.
	See https://github.com/facebook/react-native/blob/287e20033207df5e59d199a347b7ae2b4cd7a59e/packages/react-native/React/Fabric/Mounting/ComponentViews/TextInput/RCTTextInputComponentView.mm#L751-L784
	*/
	[attributedString removeAttribute:@"NSOriginalFont" range:fullRange];